Trump tweeted Renacci "has worked so hard on tax reductions, illegal immigration, the border and crime. I need Jim very badly to help our agenda and to keep making American great again. He will be a fantastic senator for the great State of Ohio, and has my full endorsement!"

.@JimRenacci has worked so hard on Tax Reductions, Illegal Immigration, the Border and Crime. I need Jim very badly to help our agenda and to keep MAKING AMERICA GREAT AGAIN! He will be a fantastic Senator for the Great State of Ohio, and has my full endorsement!

It's the first time "endorsement" and Renacci have been uttered in the same statement by Trump. But Trump had all but endorsed Renacci for the past few months.

Tuesday's tweet came after Renacci for the past year courted Trump's support, first as a Republican gubernatorial candidate and now as a Senate candidate. Renacci flew on Air Force One in February with Trump to Lunken Airport to speak in Blue Ash. He never used the word endorse, but Trump gave encouraging words to Renacci.

"Jim, get in there and fight," Trump told Renacci in Cincinnati. "Get in there and fight. We need you."

Renacci is the frontrunner in the Republican Senate primary against Cleveland-area businessman Mike Gibbons. The winner of the primary will face Sen. Sherrod Brown, D-Ohio, in the general.

Gibbons' campaign spokesman Chris Schrimpf still touted Gibbons as the most Trump-like candidate, including co-chairing Trump's campaign in Ohio.

"Voters already know that Mike Gibbons is the only conservative outsider in the race," Schrimpf wrote in an email. "Mike served as a co-chair of the Trump campaign and has a plan to have Mexico pay for the border wall."